Sins of the Soul
by Chisana-Hoshi
Summary: Detective Natsu Dragneel is stunned when FBI Agent Gray Fullbuster walks into his precinct and says his latest case is part of a string done by a high profile Serial Killer. The two must now work together to try and catch the killer before they kill again. Can the two fight their feelings long enough to do their job or will one of them just become the next victim? (GrayxNatsu yaoi)


******-Warnings: This is a Gray/Natsu fiction.-**

******-This story will be bloody and graphic and deal with themes of sexual crimes, murder, and torture.-**

******-This is an AU Crime Drama fiction, and while some things have been researched for authenticity, I do not pretend to be an expert on the workings of either Homicide Detective, FBI, or other law enforcement workings. For those wondering, I started this for a different anime and then changed my mind as I like Fairy Tail better. And for those who are wondering, this story is not based on any other story, this murder mystery and all the details are of my own creation.-**

******-Disclaimer: I do not own Fairy Tail or any of the perspective characters from the show. All other characters that appear in the story, however, are my own.**

******-Summary: Homicide Detective Natsu Dragneel is blindsided when FBI Agent Gray Fullbuster walks into his precinct and drops the bomb that his latest case is just one more in a string done by a high profile Serial Killer. The two must now work together to try and catch the man before another victim appears. Can the two fight their feelings long enough to do their job, or will one of them just become another victim?-**

**Sins of the Soul**

**Chapter One: Bad Day**

It was going to be a bad day.

A power outage caused by a rough January ice storm had caused him not only to be a hour late to work, but left him coffee-less and near frost bitten. Two things that he hated. Not having been able to stop by a Starbucks on his way in meant that if wanted his caffeine jolt to start his day he would have to rely on the horrid pot of mud the department called coffee. As for the cold, well, who honestly liked to be so cold you occasionally found yourself shaking your shoes to ensure you did not hear your toes rattling around like Tic-Tacs trapped in leather?

Detective Natsu Dragneel could only let out an annoyed breath as he walked into the station that morning. He was still exhausted and despite the fact that he knew the coffee would more resemble a cup of luke warm brown piss, every cell in his brain was screaming for a cup of java. Good morning did not happen for him without a unhealthy dose of the liquid running through his system. Many called it an addiction, however, Natsu preferred to think of it as a safety precaution. Not his own safety of course, but the safety of the idiots he was often forced to work with.

Dumping his bag in the chair to his desk, Natsu had every intention of rushing straight to the break room and by doing so avoid any of his co-workers before his senses were his own again. Yet according to the day's already stellar track record, he wasn't awarded such a reprieve. Just as his hand reached for the handle to the break room door, an arm was slung around his shoulder. The thick scent of aftershave and cologne let him know exactly who it was.

"Loke." He muttered a low warning as he tugged the door open and almost melted at the smell of brewing heaven just steps away. "No talking until I have had my coffee. First warning."

The other man tossed his head back and laughed, and Natsu had to notice that the man's orange hair was more styled this morning than its normal lion mane like appearance. A pink brow arched. His co-worker Detective Loke King only sty;ed down his hair when there was someone around that he was trying to impress. Such a fact did not bode well. Natsu shrugged his shoulders to free himself of the man's hold.

"Come on, Natsu." The man sighed as he followed the other into the break room and over to the coffee machine. "No time for your normal spunk today. We have special guests in the building!"

Natsu continued to ignore the other man as he pulled a mug from a rinse rack and made his way over to the coffee pot that was nearly singing his name at this point. One of his greatest talents (or so he liked to think) was the ability to completely tune out fellow Detective Loke and his large partner first thing in the morning. The two were made for each other. A pair of delinquents that grew up together, fighting in the school yard until a near death experience changes their life and cleans up their act. If Natsu were not so fully cynical on the idea, and the two detectives not married – one to his sister of all people – the pink haired man would have called in the perfect romance story.

Though as much as he liked to complain about the two (which was something he often did in the Chief's office on a particularly annoying day) he also had to admit they were the closet thing he had to best friends in his life. They put up with his mood swings, his odd social behavior, as well as his intense dedication to the job. There were never any questions or persuasions to 'take it easy' or 'go get laid' as past co-workers had demanded. Those two accepted the package that was Natsu Dragneel.

And just who was that? A question for the ages he supposed. At roughly about 5'7" in height

with a shock of pink hair that rose off his scalp in tousled spikes and the most unusual onyx eyes, Natsu was an enigma. He lived alone in an apartment loft with only a large blue cat named Happy for company, but he liked it that way. People bothered him in a strange way. He liked them and seemed to be gregarious enough, but he had a hard time trusting fully. It was possibly a nasty side effect from working the homicide beat. When a person saw the worst that one human could do to another, it made it harder to stomach them as an actual intelligent race or to trust them. Or maybe it was because of a smudged childhood that saw to it that he never had a reason nor desire to allow anyone to get close to him outside of odd friendships. Either way, it was his aversion to human interaction outside of work and group gatherings that made him so hard to understand.

"Come on, Natsu! Aren't ya' even going to ask who?" Loke was continuing in his pleading for attention as the shorter man ignored him still, moving on to mix sugar and cream into his coffee to make it a bearable flavor. Because his back was to the pleading detective, the man could not see the smirk that was forming on Natsu's lips at being able to torment him so easily.

Loke King, fellow homicide detective in the Boston PD. One of the few people Natsu allowed into his personal realm. There was something about him the shorter man found...refreshing. An innocence and honesty. Loke was the kind of man that seemed cruel, but would never hurt a person that did not have it coming ten times worse then he would receive. He took no bull shit, but he also did not hand any out. He left Natsu alone to do what he wanted in his life and for that he had earned a respected place as a friend.

Natsu finished mixing his morning fix, taking a sip before finally turning to Loke. The man was nearly shaking with whatever information he was waiting to unload. There was another moments pause as the shorter man took another long sip of his coffee, having to hide a cringe at the horrid taste. What he would not give for a cup of Starbucks at the moment. Hell, he would even take a one dollar McDonalds cup of java. Letting out a slow breath, he finally waved a hand towards Yusuke.

"Alright Loke, spill it." He finally gave the man the go ahead and let it pour out.

"The _Feds_ are here." The man nearly hissed out the word as he spoke. His taller frame was almost vibrating at the bit of gossip he had. "Two of 'em all suited up in the Captian's office."

Natsu let one brow arch as he took another disgusting swig of his coffee. The FBI had invaded their wonderful little home which could only mean something big was up. The Bureau only dealt with large things that spanned the nation and there was no way any local murder they had looked into was drawing their attention. Humming to himself, Natsu tapped the fingers of one hand against the counter wondering just which of their cases had caught their attention.

"Do you know which case they're here about?" He asked curious now as his ebony gaze flicked to the drawn blinds of the Captain's office.

"Nah." Loke shrugged, more at ease now that he had finally told Natsu what he wanted to do. "The two of them walked in and went straight into Erza's office and then the blinds dropped. So it's gotta be something huge."

Natsu's eyes continued to peer at the blocked off windows and tried to go over the recent cases in his head. There was the prostitute beaten to death in an alley, a man shot in a bank parking lot, and a woman found dead in her home.

He knew it was not the prostitute, as the crime had already been solved. The woman had slept with a rich man in the hope to black mail him with the threat of spilling the beans to his wife, the one who really made the money. In a panic he had smashed her head in with a paper weight in an attempt to shut her up and keep his wallet fat.

It also was not the man in the alley. Loke and Elfman were lead on that case and they already had a surveillance tape of the crime. A local known drug user had tried to rob the man after he visited the ATM so that he could get his next hit. The man had fought back and the gun went off. All they were waiting on now was the beat walkers to find him and bring him in.

That only left the woman and Natsu had to curse to himself. That was his case and was still unsolved and no suspect in sight. The young woman had been found beaten and raped in her own bedroom by a nervous neighbor that had noticed she had not been seen in a few days. Her death had been caused by blood loss from slit wrists. There was no main suspect, not even a boyfriend or ex-boyfriend to question. Which meant that the only brutal murder that was still up in the air was the one he was in charge of.

Just at that moment the door to Captain Erza's office was yanked open so hard that it made the two detectives jump in surprise. The tall red head stepped out, scanning the desks before locking on the window of the break room. Her brown orbs narrowed and the annoyed look in them was hard to miss from even across the bullpen. Both men flinched.

"No." Natsu muttered, looking down into his coffee cup and hoping that he would vanish into the brown liquid. The last thing he wanted was to have the FBI begin pushing into his investigation. They were often pushy blow hards that had a superiority complex, acting as though they were better then the beat cops. Their type always grated on him. Every law official from the FBI straight on down to the sheriff in a town of 98 people deserved respect, in his opinion. Granted some places had more risk involved but he had read enough stories about "local cop killed on the job" to know there was danger every where in the job.

"Dragneel, my office now!" Erza bellowed across the building before slamming the door shut again without so much as another word.

"Uh oh." Loke chuckled, reaching forward to pat Natsu on the shoulder in a fake show of sympathy. "That was the Captain's serious voice. You better put a hustle in your step, Pinky. Don't want to keep those important agents waiting!"

"Fuck you, Loke." Natsu growled out. Turning to the sink he dumped the rest of his coffee down the sink, now wishing more then ever that he had said screw the extra 15 minutes he would have been late and grabbed Starbucks on his way in.

He knew today was going to be a bad day.

**-Sins-of-the-Soul-**

The agents seemed out of place, not only in Erza's office, but in the precinct as a whole. Their suits were expensive and seemed to have been professionally pressed as every crease was flawless. They were deep shades of ebony with white button down shirts and red ties. It made Natsu consider the idea that he was undressed for work in his normal jeans and black ribbed turtle neck sweater that fit his chest tightly. His badge was perched on his belt and his gun rested in a classic shoulder holster.

Both agents were oddly elegant looking. One had long dark purple hair that she wore loose, letting the shimmering tresses fall to just pass her shoulders. Large brown eyes watched him gently from a face with pale skin. Natsu only gave her a quick glance before moving on to observe the next one.

Seeing the next agent stopped him in his tracks. Natsu could not explain why but this caused his breath to lock in his lungs. The man was tall with raven locks that fell in shaggy spikes. Pale blue eyes regarded him with a calm and intelligence that Natsu knew would likely stun him even further.

It was not until the man let a raven brow arch that Natsu realized that he has been staring rather intently. He tore his eyes away with a scowl, grunting to himself as he threw his weight into a chair across from Erza's desk. His onyx eyes narrowed to show his annoyance. It normally worked on most people, but his Captian was one of the few that it had no effect on.

"You were late, Detective." Erza muttered, scowling right back. It was obvious she was no more pleased the FBI was here then Natsu was. Which was normal. Those that ran precincts never liked bigger dogs sniffing around their territory.

"Yea, ice storm took out my power." He grunted in response. There was nothing he liked about getting scolded in front of strangers. "No power means no alarm. No alarm means...?"

"Your ass gets an extra hour of sleep."

Natsu grinned at his commanding officer with a slow nod of his head. "See, all that time behind a desk hasn't dulled your sleuthing skills."

It was a jab, but Natsu felt his Captain deserved it for trying to puff herself up in front of the Feds. Natsu could understand it, the want to prove herself in front of those that held rank over even her. Such a tactic might have gone untouched by another detective, but he could not. Erza only glared back at him as if waiting for the shorter man to apologize. Well that would be a cold day hell. And the Captain seemed to know that and let out a sigh as she moved on.

"Natsu, I'd like you to meet Agent Gray Fullbuster and Agent Ultear Milkovich from the Federal Bureau of Investigation." The Captain waved a hand towards the two agents that stood beside her desk. "They are here in regards towards the case that you picked up two days ago."

"The Suicide Homicide found in her own home?" Natsu questioned. He knew of course that was what the Captain was referring to, but he wanted to hear them confirm it. He was always the Detective; be the one to always be asking the questions, getting this answers instead of giving them.

It was then that the stunning raven haired man stepped forward, offering Natsu a leisurely smile. It was a gesture that left the shorter man feeling tight inside. That smile was earth moving and Natsu felt his mouth go dry. Damn, with that one around keeping his cool might be a tad harder then normal.

"Agent Fullbuster." He offered a clarification as to which name was his. "We're here in regards to the investigation of that woman's death. The details of it caught our attention."

"And why's that?" Natsu arched a brow to emphasis his question.

Agent Fullbuster only smiled in response to the question. "Tell us what you have on the case so far, Detective Dragneel."

Natsu grinned. This agent was smart. He had obviously seen that Natsu was trying to control the situation with his questions and was forcing the conversation in a way that would force him to give answers instead of getting them. The raven haired agent was good at what he did. The shorter man grinned. Too bad he was better.

"You said the details caught your interest, Agent Fullbuster." He mused with a smirk. "Why don't you tell me?"

The agent only grinned back. The expression that had made his mouth dry before now only caused annoyance in the pinkette. He scowled back, giving the man the same look he did a suspect in the integration room. It was not that he was trying to intimidate answers out of the man, he just wanted to show that he would not be railroaded off his own case because the Feds decided it was interesting enough for them to be a part of.

"Damn it, just answer the man, Dragneel!" The Captain suddenly barked, snapping both men out of their stare down.

Natsu's scowl now turned towards his commanding officer to show her his dislike towards the situation. It was like silent plea for the woman to side with him and end this stupid little dance. The Captain only glared back, letting her brown orbs return their own voice of agitation. The short man finally sighed and threw up his hands in surrender.

"Her neighbor called it in, said the girl hadn't been seen in a few days and when she went to check on her, she noticed a funny smell and called the cops. They got the landlord to let them in and that's where we found her." He muttered, crossing his arms tightly over his chest. "Identification in the apartment told us the vic was 25 year old Karen Lilica, a law student at Harvard. Father was paying for her apartment off campus. According to other tenets and classmates she kept to herself, had very few friends – if any – no boyfriend and apparently no ex-boyfriend either. Seems she lead a very sheltered life and never dated, focused solely on her studies.

"As for the crime scene, she was found in her own bed, beaten severely. Broken bones, heavy contusions, even internal damage. Ligature marks on the hands and ankles suggested she had been bound to the bed and raped, likely more than once given the amount of damage to the genitalia. The cause of death, however was slit wrists that caused her to bleed out. First uniforms on scene thought it was a suicide, but a more detailed look leads to homicide."

"Because there was blood soaked into the cloth that was used to bind her, white silk scarves." Agent Fullbuster suddenly filled in, causing Natsu to blink. "There was also no weapon found near the body or in the apartment with a trace of her blood to indicated she had used it on herself."

Natsu could only stare at the agent in shock. The information about the white scarves had been held from the press and reports. Little things like that were always held back to help the investigation. It let them know if someone was falsely admitting to the crime in an attempt to protect the real killer. So there was no way this Agent, who had just rolled into town, should know of them.

"How did you know about the scarves?" He asked sharply.

The agent only continued with that breathtakingly infuriating smile, hoisting a briefcase up onto the desk. Natsu watched the movements carefully to determine what was about to happen. It was obvious there was something in that case that was intended to shock him or else there would not be all the pop and circumstance with revealing it. The detective would not be impressed though. He had dealt with FBI agents before and knew that they liked to work with a flair.

Fullbuster pulled a folder out and handed it to Natsu with a small nod, indicating the man was to open them. Natsu raised a brow and did just that. Twelve pictures were tucked neatly inside, each one of a man or woman who was dead, found in a similar situation as his own victim. Beaten heavily, tied to a bed with white silk scarves, and wrists slit to leave them surrounded in blood. Natsu could only flip through them in silence. Twelve other people, none of them looking alike, but each one laid out in the same final resting position. His stomach clenched up in dread.

"What is all this?" He asked, flipping the folder closed. He regretted the question because he already knew the answer and did not want to hear it.

"Those are murders that have happened over the past six years across the country." Fullbuster was already confirming Natsu's thoughts. "Two people with nothing linking them to one another at all killed within weeks of each other, one pair a year. Each pair in different states, but all the same M.O. Your case, Karen Lilica, matches all the details of these cases, including the ones that were left out of the reports. The white scarves and the lack of supposed suicide weapon."

Fullbuster paused there and Natsu knew he was suppose to fill in the rest, confirm his worst fears about what was going down in his own city. The shorter man refused. Just thinking it was bad enough but to voice it would mean that the worst possible thing was about to happen. Something he had yet to deal with on his time in the force and something he never wanted to deal with. He had dreams of retiring without being pulled into one of these three ring circus acts.

However when Natsu would not put words to his thoughts, it seemed neither Agent was willing to let them go unsaid. Agent Milkovich shifted, her leather heels creaking loudly in the silence that filled the office. Fullbuster did not seem at all ruffled by it though and shifted his hip to sit on the desk in front of Natsu. He leaned forward, long shaggy spikes of rave hair falling into his eyes as his blue orbs locked on Natsu's onyx ones.

"It seems a high profile serial killer has moved into your neighborhood, Detective Dragneel."

Yes. It was going to be a bad, awful, shitty fucking day.

**-My apologies if the chapter seems rush, but I wanted to quickly set the ground work for the actually story plot. Things will start to 'slow down' now in the sense that more character description and such will be added. Enjoy and please review to let me know what you think!**

**-Police terms used:**

**Bullpen:**** This is often what the area of a police station where the officer's desk are located are known as.**

**Detective:** **An actual rank in United States Police Force. It is ranked second, above beat cops (also known as 'Officers' or 'Troopers'. It is also a general term for any law enforcement official that's job entails investigative work over 'working the beat'. In these cases it may have no direct link towards their rank. (IE: A Sargent in Homicide would still introduce themselves as 'Detective -name-' rather then Sargent.**

**Beat Walkers:**** A nick name given to a trooper or officer that still works in a uniform and does patrols.**


End file.
